1. Technical Field of the Invention
The present invention relates to a process of aligning and retaining alignment of a series of rotating equipment coupled together for cooperative operation. More specifically, the observation, recordation, and utilization of various characteristics of the equipment, equipment set up, and operational characteristics to predict, optimize, and retain alignment therebetween.
2. Background Art
Rotating machinery, equipment, or other devices can be provided in many form factors, such as an electrical motor, a combustion motor, a pump, a transmission or other gear box, and the like. Rotating equipment is commonly configured coupling at least two rotating devices together, referred to as a machine train. The configuration can couple two or more like devices together, such as motors, pumps, and the like to provide serial addition of power or parallel functionality, respectively. Alternatively, the configuration can couple two or more dissimilar devices together, such as coupling a motor and a transmission, coupling a motor and a pump, and the like to provide joint functionality. In any configuration, alignment between two adjacent components impacts the efficiency and reliability of the equipment.
Many factors can impact alignment between equipment. Alignment of the equipment dictates that the equipment remains stationary, and thus the alignment process is completed when the equipment is completion in a non-operational state. Additionally, the alignment process is commonly completed in an ambient environment. Unfortunately, this requirement removes a number of variables, which impact the alignment during operation, where those variables are only present during operation. Examples include thermal effects on each element of the equipment, balance of rotating elements, changes in compressive components such as soft feet, changes due to torsional effects, and the like. The operational environment commonly changes in temperature, which affects the mounting area, the equipment, and the like. In most operational scenarios, the equipment and operating environment increases in temperature, impacting the alignment between adjacent equipment.
Each individual machine arrangement is different resulting from each arrangements unique characteristics. Even identical sets of machinery can dictate different terms for alignment. Factors of each configuration including location, mounting schematics, and the like affect the alignment.
Laser alignment was introduced in the 1980's. This process utilized one or more diode lasers and detectors (PSD's). The PSD's were able to detect fairly accurately (within 10 μm's) relative positioning between two adjacent shafts. Information is provided to the service person through a display unit. The system determines what information needs to be conveyed to the service person in order to direct the service person on what is required to optimize alignment between two adjacent components. The display unit can be provided in any of many known form factors, including a computer, preferably comprising a wireless interface. Software converts the detector signals into a set of instructions in an understandable format for the operator or service person. Alignment or registration between two adjacent components is commonly defined in two components:                A. Angular misalignment        B. Parallel or offset misalignment        
Parallel registration can be defined in two directions, horizontal and vertical, basically referring to respectively X-axis and Y-axis.
Another component that could be considered is end-to-end registration, ensuring sufficient gap is provided for thermal expansion, vibration, and the like.
The fundamental setup of the laser alignment instrumentation has remained unchanged since its inception in the 1980's, including a diode laser based system with a detector and a portable computer with standard alignment software.
As technology has evolved, the technological advances have been integrated into the process. Examples include the introduction of wireless technology changed the method of data transfer from the laser/detector to the portable computer, by removing cables previously connecting therebetween. Although technology has advanced and aided the user in certain areas, the overall fundamentals of the process, including the hardware and respective software have remained unchanged over the years.
Most craftspeople that align machinery already understand the phenomenon of what is usually called machinery “soft foot.” Soft Foot is a common term used for machine frame distortion. The distortion is caused when one or more feet of a machine differ in height from the others. This in turn may be due to differences when the machine was manufactured, a squishy footage with oil film etc. between foot and base, a bent foot, or it may be induced by a pipe to which the machine is attached (e.g. a pipe on top of a pump), which prevents the machine from touching all its feet to its base.
As many vibration specialists have never actually aligned machinery, they may have heard of “soft feet” but may not always understand the result in vibration. Soft feet can cause increased vibration amplitudes. Although “soft feet” does not necessarily magnify machine vibration, it should be reduced for many reasons, including preventing vibration magnification.
The current alignment process includes the following steps:                A. Position alignment equipment as directed for aligning two adjacent rotating machines;        B. Measure the soft foot;        C. Correct the soft foot;        D. Measure the current alignment;        E. Enter a tolerance into the software, wherein the tolerance may be a target;        F. Correct any misalignment between two adjacent rotating machines until the alignment is within the established tolerance or target; and        G. Record the measurements, such as entering the measurements into an electronic database and optionally uploading the information to a remote database.        
It is well know that unless soft foot conditions are checked, alignment may be impossible or the improvement in alignment may be short-lived.
The current alignment process is dependent upon the experience level of the alignment engineer. Most experienced alignment engineers are disappearing. Each configuration between adjacent rotating machines is different, thus being unique in alignment. The level of experience of the alignment engineer impacts the time and quality of the alignment. Lack of knowledge respective to the details is only a portion of the problem. The lack of awareness that results in not searching for the answer contributes to the problem. Another contributing factor is when the alignment engineer fails to apply the correct details, which is certainly a problem.
Long term reliability of the trained rotating machinery is dependent upon a sustained alignment. Misaligned shafts which are coupled together can cause inefficient transfer of energy or torque from a drive shaft to a torque receiving shaft. Misalignment can cause premature wear and failure of components, seal damage which allows leaks of lubricants and other fluids, and the like. Premature wear and failure can result in excessive downtime, higher operating costs, and the like.
Thus, what is desired is a process to identify when the alignment between coupled shafts of adjacent rotating machines shifts where the alignment is no longer within an acceptable tolerance range.